A common video monitoring network is shown in FIG. 1, and the video monitoring network includes a camera, a server, a client, and an IP network for interaction between the three. The camera mainly performs collection and coding of audio and video data, and the like. The server mainly performs camera device management, client management, service process management, data storage, and the like. The client mainly provides an operation and management entrance for video services.
However, in an existing solution, a user can only estimate a visual angle of the camera but not able to acquire accurate information about the visual angle.